| 摘要 |
A method for a pair of redundant storage controllers to ensure reliable cached write data transfers to storage device logical volumes is provided. The method includes maintaining metadata including a first number identifying which controller currently owns the volume, a second number identifying which controller previously owned the volume, a third number identifying which controller is a preferred owner of the volume, and an indication if the volume is write protected. The method also includes determining if all volumes currently owned by the controller are write protected. If all volumes currently owned by the controller are write protected, then the method includes verifying that the second controller is working and transferring cache data from the second controller to the first controller. If all volumes currently owned by the first controller are not write protected, then the method includes updating the second number and placing all volumes online. |
| 主权项 |
1. A method for a pair of redundant storage controllers comprising a first and a second storage controller to ensure reliable cached write data transfers to storage device logical volumes, comprising:
maintaining, by the pair of redundant storage controllers, metadata for the logical volumes, wherein for each logical volume the metadata comprises:
a first number identifying which storage controller of the a pair of redundant storage controllers currently owns the logical volume;a second number identifying a storage controller that previously owned the logical volume;a third number identifying which storage controller of the pair of redundant storage controllers is a preferred owner of the logical volume; andan indication if the logical volume is write protected; determining, by the first storage controller, if all logical volumes currently owned by the first storage controller are write protected, wherein the first storage controller owns logical volumes where the first number identifies the first storage controller, wherein the second storage controller owns logical volumes where the first number identifies the second storage controller;
if all logical volumes currently owned by the first storage controller are write protected, then:
verifying, by the first storage controller, that the second storage controller is working properly; andtransferring write cache data from the second storage controller to the first storage controller; andif all logical volumes currently owned by the first storage controller are not write protected, then:
updating, by the first storage controller, the second number to identify the first storage controller for logical volumes where the first number identifies the first storage controller;resetting, by the first storage controller, the indication that the logical volume is write protected for logical volumes where the first number identifies the first storage controller and the indication that the logical volume is write protected is set; andplacing, by the first storage controller, all logical volumes online and accessible to host computers coupled to the pair of redundant storage controllers. |
